1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Copyright (C) 2009-2010 IBM Corporation
4 *
5 * Authors:
6 * Mimi Zohar <zohar@us.ibm.com>
7 */
8
9#ifdef pr_fmt
10#undef pr_fmt
11#endif
12
13#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
14
15#include <linux/types.h>
16#include <linux/integrity.h>
17#include <crypto/sha1.h>
18#include <crypto/hash.h>
19#include <linux/key.h>
20#include <linux/audit.h>
21#include <linux/lsm_hooks.h>
22
23enum evm_ima_xattr_type {
24 IMA_XATTR_DIGEST = 0x01,
25 EVM_XATTR_HMAC,
26 EVM_IMA_XATTR_DIGSIG,
27 IMA_XATTR_DIGEST_NG,
28 EVM_XATTR_PORTABLE_DIGSIG,
29 IMA_VERITY_DIGSIG,
30 IMA_XATTR_LAST
31};
32
33struct evm_ima_xattr_data {
34 /* New members must be added within the __struct_group() macro below. */
35 __struct_group(evm_ima_xattr_data_hdr, hdr, __packed,
36 u8 type;
37 );
38 u8 data[];
39} __packed;
40static_assert(offsetof(struct evm_ima_xattr_data, data) == sizeof(struct evm_ima_xattr_data_hdr),
41 "struct member likely outside of __struct_group()");
42
43/* Only used in the EVM HMAC code. */
44struct evm_xattr {
45 struct evm_ima_xattr_data_hdr data;
46 u8 digest[SHA1_DIGEST_SIZE];
47} __packed;
48
49#define IMA_MAX_DIGEST_SIZE HASH_MAX_DIGESTSIZE
50
51struct ima_digest_data {
52 /* New members must be added within the __struct_group() macro below. */
53 __struct_group(ima_digest_data_hdr, hdr, __packed,
54 u8 algo;
55 u8 length;
56 union {
57 struct {
58 u8 unused;
59 u8 type;
60 } sha1;
61 struct {
62 u8 type;
63 u8 algo;
64 } ng;
65 u8 data[2];
66 } xattr;
67 );
68 u8 digest[];
69} __packed;
70static_assert(offsetof(struct ima_digest_data, digest) == sizeof(struct ima_digest_data_hdr),
71 "struct member likely outside of __struct_group()");
72
73/*
74 * Instead of wrapping the ima_digest_data struct inside a local structure
75 * with the maximum hash size, define ima_max_digest_data struct.
76 */
77struct ima_max_digest_data {
78 struct ima_digest_data_hdr hdr;
79 u8 digest[HASH_MAX_DIGESTSIZE];
80} __packed;
81
82/*
83 * signature header format v2 - for using with asymmetric keys
84 *
85 * The signature_v2_hdr struct includes a signature format version
86 * to simplify defining new signature formats.
87 *
88 * signature format:
89 * version 2: regular file data hash based signature
90 * version 3: struct ima_file_id data based signature
91 */
92struct signature_v2_hdr {
93 uint8_t type; /* xattr type */
94 uint8_t version; /* signature format version */
95 uint8_t hash_algo; /* Digest algorithm [enum hash_algo] */
96 __be32 keyid; /* IMA key identifier - not X509/PGP specific */
97 __be16 sig_size; /* signature size */
98 uint8_t sig[]; /* signature payload */
99} __packed;
100
101/*
102 * IMA signature version 3 disambiguates the data that is signed, by
103 * indirectly signing the hash of the ima_file_id structure data,
104 * containing either the fsverity_descriptor struct digest or, in the
105 * future, the regular IMA file hash.
106 *
107 * (The hash of the ima_file_id structure is only of the portion used.)
108 */
109struct ima_file_id {
110 __u8 hash_type; /* xattr type [enum evm_ima_xattr_type] */
111 __u8 hash_algorithm; /* Digest algorithm [enum hash_algo] */
112 __u8 hash[HASH_MAX_DIGESTSIZE];
113} __packed;
114
115int integrity_kernel_read(struct file *file, loff_t offset,
116 void *addr, unsigned long count);
117
118#define INTEGRITY_KEYRING_EVM 0
119#define INTEGRITY_KEYRING_IMA 1
120#define INTEGRITY_KEYRING_PLATFORM 2
121#define INTEGRITY_KEYRING_MACHINE 3
122#define INTEGRITY_KEYRING_MAX 4
123
124extern struct dentry *integrity_dir;
125
126struct modsig;
127
128#ifdef CONFIG_INTEGRITY_SIGNATURE
129
130int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
131 const char *digest, int digestlen);
132int integrity_modsig_verify(unsigned int id, const struct modsig *modsig);
133
134int __init integrity_init_keyring(const unsigned int id);
135int __init integrity_load_x509(const unsigned int id, const char *path);
136int __init integrity_load_cert(const unsigned int id, const char *source,
137 const void *data, size_t len, key_perm_t perm);
138#else
139
140static inline int integrity_digsig_verify(const unsigned int id,
141 const char *sig, int siglen,
142 const char *digest, int digestlen)
143{
144 return -EOPNOTSUPP;
145}
146
147static inline int integrity_modsig_verify(unsigned int id,
148 const struct modsig *modsig)
149{
150 return -EOPNOTSUPP;
151}
152
153static inline int integrity_init_keyring(const unsigned int id)
154{
155 return 0;
156}
157
158static inline int __init integrity_load_cert(const unsigned int id,
159 const char *source,
160 const void *data, size_t len,
161 key_perm_t perm)
162{
163 return 0;
164}
165#endif /* CONFIG_INTEGRITY_SIGNATURE */
166
167#ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
168int asymmetric_verify(struct key *keyring, const char *sig,
169 int siglen, const char *data, int datalen);
170#else
171static inline int asymmetric_verify(struct key *keyring, const char *sig,
172 int siglen, const char *data, int datalen)
173{
174 return -EOPNOTSUPP;
175}
176#endif
177
178#ifdef CONFIG_IMA_APPRAISE_MODSIG
179int ima_modsig_verify(struct key *keyring, const struct modsig *modsig);
180#else
181static inline int ima_modsig_verify(struct key *keyring,
182 const struct modsig *modsig)
183{
184 return -EOPNOTSUPP;
185}
186#endif
187
188#ifdef CONFIG_IMA_LOAD_X509
189void __init ima_load_x509(void);
190#else
191static inline void ima_load_x509(void)
192{
193}
194#endif
195
196#ifdef CONFIG_EVM_LOAD_X509
197void __init evm_load_x509(void);
198#else
199static inline void evm_load_x509(void)
200{
201}
202#endif
203
204#ifdef CONFIG_INTEGRITY_AUDIT
205/* declarations */
206void integrity_audit_msg(int audit_msgno, struct inode *inode,
207 const unsigned char *fname, const char *op,
208 const char *cause, int result, int info);
209
210void integrity_audit_message(int audit_msgno, struct inode *inode,
211 const unsigned char *fname, const char *op,
212 const char *cause, int result, int info,
213 int errno);
214
215static inline struct audit_buffer *
216integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
217{
218 return audit_log_start(ctx, gfp_mask, type);
219}
220
221#else
222static inline void integrity_audit_msg(int audit_msgno, struct inode *inode,
223 const unsigned char *fname,
224 const char *op, const char *cause,
225 int result, int info)
226{
227}
228
229static inline void integrity_audit_message(int audit_msgno,
230 struct inode *inode,
231 const unsigned char *fname,
232 const char *op, const char *cause,
233 int result, int info, int errno)
234{
235}
236
237static inline struct audit_buffer *
238integrity_audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, int type)
239{
240 return NULL;
241}
242
243#endif
244
245#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
246void __init add_to_platform_keyring(const char *source, const void *data,
247 size_t len);
248#else
249static inline void __init add_to_platform_keyring(const char *source,
250 const void *data, size_t len)
251{
252}
253#endif
254
255#ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
256void __init add_to_machine_keyring(const char *source, const void *data, size_t len);
257bool __init imputed_trust_enabled(void);
258#else
259static inline void __init add_to_machine_keyring(const char *source,
260 const void *data, size_t len)
261{
262}
263
264static inline bool __init imputed_trust_enabled(void)
265{
266 return false;
267}
268#endif
269